SURGE Series: Lightning and Transient Protectors

Overview

Wiring, particularly long horizontal wiring, can convert transient electrical fields to destructive voltages at sensors and data logger terminals. Transient protection equipment can be used to divert these transients to ground, increasing installed system reliability.

The SURGE Series of transient protectors consist of multi-stage devices which includes three terminal gas discharge tubes, thyristor crowbar devices, and coordinating resistors. They are capable of protecting against high-speed (100 volts per microsecond) transients of up to 20,000 amps, letting only 77 volts through before clamping to 4 volts. The protector is housed in a NEMA-4X enclosure or in a compact T35 DIN-rail housing with screw-terminal input/output and ground connection through the DIN rail, simplifying connections, and facilitating good signal practices: i.e. labeling, shielding, and routing outside cables away from protected lines.

In normal operation, the protector appears as a low resistor in series with each wire, typically having no effect on operation. During a transient, the 4 signal lines and up to 2 shield lines are clamped to ground. Once the transient is over, the device self-resets, allowing normal operation to resume. The protector is suitable for use with most devices, including vibrating wire sensors, data loggers, 4-20 mA transmitters, and other DC-powered sensors.